Paper of the week: Effects of prenatal exposure of pthalates

Pthalates are esters of pthalic acid that are commonly added to plastics but also are found in diverse products ranging from cosmetics to pharmaceutical pills. As could be expected, studies that monitor phthalate metabolites in human populations have shown that they are widely present. Over the years, there have been many concerns over their effect on human health notably as hormonal disrupting agents. This has led to the regulation of some phthalates in consumer products in Europe and the United States, which in some cases,have been replaced with others. Recent evidences indicate that endocrine disruption might only be a tip of the iceberg and that pthalates might have other health effects as well.

It is well known that maternal exposure of pollutants make their way to the offspring and in many cases can have deleterious consequences. It appears that this dogma can also be applied to the case of the pthalates. In a study by Engel et al published in Environmental health perspectives,

http://ehp03.niehs.nih.gov/article/fetchArticle.action;jsessionid=E899A81379071E8E095EF53E962F597F?articleURI=info%3Adoi%2F10.1289%2Fehp.0901470

the authors questioned whether there was any association between prenatal phthalate exposure to the behavior of offspring. The study occurred in a multiethnic prenatal population enrolled in the Mount Sinai Children’s Environmental Health Study in New York City between 1998 and 2002. Urine samples of mothers during the third-trimester of pregnancy was collected and analyzed for phthalate metabolites. Subsequently, cognitive and behavioral development of the children was assessed between the ages of 4 and 9. Interestingly, the scientists found that increased concentrations of low-molecular-weight (LMW) phthalate metabolites in the mothers were associated with poorer scores on aggression, conduct problems, attention problems, and depression in the children. These results led them to conclude that behavioral domains adversely associated with prenatal exposure to LMW phthalates in this study are commonly affected in children clinically diagnosed with conduct or attention deficit hyperactivity disorders.

This study and several of its predecessors, extend the known adverse effects of pthalates, which calls for increased caution. What is urgently needed are more hard core studies elucidating the toxicology of pthalates and their metabolites, that will help us understand the consequences of exposure. However, these studies will take time; the evidence at hand should motivate nations to re-evaluate their policies on pthalates and enforce strict regulations.

Engel SM, Miodovnik A, Canfield RL, Zhu C, Silva MJ, Calafat AM, & Wolff MS (2010). Prenatal phthalate exposure is associated with childhood behavior and executive functioning. Environmental health perspectives, 118 (4), 565-71 PMID: 20106747